Abstract

The ability of chemically synthesized 3-deoxy-lalpha-hydroxyvitamin D3, an analog of the biologically active form of vitamin D3, (lalpha,25-dihydroxyvitamin D3), to stimulate intestinal calcium transport was assessed. The 3-deoxy analog acted significantly more rapidly than vitamin D3 and only slightly slower than lalpha,25-dihydroxyvitamin D3. Comparison of the dose-response curves of these three vitamin D derivatives emphasizes the importance of the 3beta-hydroxyl group to biological activity.